Compact photographic camera lens system having an aspherical surface of short overall length

ABSTRACT

A compact photographic camera lens system for use in a compact camera using Leica size film. In order to reduce the overall length of the lens system and the number of constituent lens elements of the lens system, an aspherical surface is introduced into part of the lens system and aberrations are properly corrected up to a field angle of approximately 63 DEG .

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a compact photographic camera lenssystem having an aspherical surface of short overall length, and moreparticularly, to a compact photographic camera objective using Leicasize film, which is so designed that an aspherical surface is introducedinto part of the lens system to minimize overall length as well asreducing the number of lens component of the lens system and where theaberrations of the lens system are properly corrected up to a fieldangle of around 63°.

(b) Description of the Prior Art

In general, a field angle of around 63° is chosen for compactphotographic camera objectives using Leica size film. In order to designlens systems of this kind as very compact systems having a telephotoratio of 1.0 and lower, it is necessary to locate the rear principalpoint of the entire lens system before the first lens surface. For thepurpose of satisfying this requirement, it is considered to adapt a lenstype generally used as telephoto lenses comprising a front lens groupdesigned as a converging lens system and a rear lens group designed as adiverging lens system. With the telephoto type lens system, however, itis extremely difficult to properly correct offaxial aberrations.

A lens system construction similar to that used in the present inventionis disclosed in the Japanese Laid Open Patent Application No. Sho55/1980-73014 in which a lens system is formed of only spherical lenssystems. On the other hand, a lens system in which aspherical surfacesare formed on both sides of a fourth lens component is disclosed in theJapanese Laid Open Patent Application No. Sho 56/1981-59217 of the sameinventor which has been made with the object of improving performance ofthe lens system in the former application in the marginal portions ofthe image plane. Specifically, a compact photographic camera lens systemof short overall length is provided by introducing an aspherical surfaceat an extremely effective position for correcting aberrations inmarginal portions of an image plane so that the aberrations are properlycorrected. To achieve this purpose, the prior application indicates thatthe sufficient requirement is to introduce two aspherical planes intopart of a lens system. However, the aspherical surface isdisadvantageous in manufacturing due to difficulty of processing andinspection and accordingly presents an unavoidable expense. Therefore,it is apparently advantageous in manufacturing to reduce the number ofaspherical surfaces to one. In this case, a problem is that, even if thenumber of aspherical surfaces to be introduced is reduced to one, howthe same lens performance as that of a lens having two asphericalsurfaces can be obtained.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compactphotographic camera lens system having a telephoto ratio smaller than1.0 which is so adapted as to have a very short overall length by usinga lens system of the telephoto type including four components of fourlens elements and by introducing an aspherical surface into only oneside of a fourth lens component and which is arranged such that theaspherical surface has an especially large aspherical constant of thesixth order and a small aspherical constant of the lower orders than thefourth order so as to be effective only to the higher order correctionregarding offaxial rays, thereby properly correcting offaxialaberrations without adversely affecting paraxial aberrations so that afield angle up to around 63° can be obtained and the overall length ofthe lens system can be minimized.

According to the present invention, the number of aspherical surfaces islimited to at most one so as to facilitate manufacturing and yet whereinnoticeable effect on the correction of aberrations can be obtained evenwith one aspherical surface which is designed such that terms higherthan the sixth order of the aspherical surface is made much larger thanterms lower than the fourth order and the airspace between a front andrear lens groups is increased. As shown in aberration characteristicscurves in the accompanying drawings, correction of aberrationsparticularly at a position of around 0.8 to 0.9 times the maximum imageheight is fully improved compared with a spherical surface system and itis possible to obtain the same effect as that of a system having twoaspherical surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating a lens construction according toEmbodiments 1 and 2 of the present invention;

FIG. 2 is a diagram illustrating aberration characteristics curves of alens system of Embodiment 1 shown in FIG. 1;

FIG. 3 is a diagram illustrating aberration characteristics curves of alens system of Embodiment 2 shown in FIG. 1;

FIG. 4 is a sectional view illustrating a lens construction according toEmbodiment 3 of the present invention; and

FIG. 5 is a diagram illustrating aberration characteristics curves ofEmbodiment 3 shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A lens system of the present invention is an objective for use inphotographic cameras which comprises a first positive meniscus lenscomponent having a convex surface on the object side, a second biconcavelens component, a third biconvex lens component consisting of a single(FIG. 1) or compound (FIG. 2) lens and a fourth negative meniscus lenscomponent, said fourth lens component having an aspherical surface onthe image side and being so designed as to satisfy the followingconditions:

    0.45f<f.sub.1.2.3 <0.75f                                   (i)

    0.15f<d.sub.6 <0.2f                                        (ii)

The condition (i) defines the resultant focal length from the first lenscomponent to the third lens component. When the lower limit of thecondition (i) is exceeded, the overall length of the lens system can beadvantageously reduced but correction of offaxial aberrations intendedin the present invention is insufficient even if an aspherical surfaceis introduced. When the upper limit of the condition (i) is exceeded,the overall length can not be reduced. The condition (ii) defines anairspace d₆ between the front lens group of the so-called convergentlens system from the first lens component to the third lens componentand the rear lens group of the so-called divergent lens system of thefourth lens component. When the airspace d₆ increases to some extent theoverall length of the lens system is advantageously reduced andaberrations are advantageously corrected. For example, when the airspaced₆ is increased with the same overall length, refracting powers of thefront and rear lens groups are reduced with the result that aberrations,especially spherical aberrations and astigmatism, are advantageouslycorrected. There is a tendency to reduce sagittal and meridionalcurvature of fields so that astigmatism in the marginal portions of animage plane can be reduced. However, the increase of the airspace d₆attended with the increase of asymmetry in the front and rear groups ofa lens system. Furthermore, outward coma and distortion of the pincushion type are apt to be produced. However, these can problems besolved by making the surface of the fourth lens component on its imageside an aspherical surface deviated on the object side from the standardspherical surface (r₈).

As described above, spherical aberration, astigmatism, coma anddistortion are properly corrected and the imaging performance in themarginal portions of the image plane which is intended in the presentinvention is also corrected properly.

The introduced aspherical surface is intended for correction of higherorder aberrations with respect to an image plane (coma higher than thefifth order, distortion higher than the fifth order) and is required tohave no adverse effect on spherical aberrations which can be fullycorrected in a spherical system. Such requirements are most effectivelyachieved by introducing an aspherical surface which has a low offaxialray, a higher principal ray, smaller aspherical constants which arelower than the fourth order on the image side plane of the fourth lenscomponents than that on the object side plane thereof and largeaspherical constants higher than the sixth order.

Specifically, assuming that an equation of the aspherical surface isexpressed as follows: ##EQU1## and the sum of all terms other than theabove spherical component is expressed as follows:

    Ay.sub.8.sup.4 +By.sub.8.sup.6 +Cy.sub.8.sup.8 +Dy.sub.8.sup.10 =Δx.sub.8,

it is preferred that the following conditions are satisfied:

    |Δx.sub.8 |≦5×10.sup.-4 ·f(y.sub.8 ≦0.1f)

and

    |Ay.sub.8.sup.4 |≦0.1|By.sub.8.sup.6 |

(where at least the limits of 0.15f≦y₈ ≦0.2f).

The fact that spherical aberrations and aberrations of lower ordersregarding paraxial rays are properly corrected is disclosed in theJapanese Laid Open Patent Application No. Sho 55/1980-73014.Accordingly, it is preferred that the foregoing conditions are satisfiedin order than pincushion type distortion is not remarkably produced byproducing higher order distortion on the negative side without adverselyeffecting aberrations corrected in the Japanese Patent Application,higher order coma flare is removed and a sufficient quantity of marginalrays is ensured by enhancing the aperture efficiency over marginalportions of field angle. The deviation from these conditions willdisadvantageously increase distortion and lower order aberrationsregarding paraxial rays.

In addition, the following conditions (iv) through (viii) are imposedfor further improvements in correction of aberrations.

    0.02f<d.sub.4 <0.087f                                      (iv)

    0.09f<d.sub.5 <0.16f                                       (v)

    0.02f<d.sub.2 <0.04f                                       (vi)

    0.5f<|f.sub.4 |<2.0f                     (vii)

    ν.sub.3 <58.0                                           (viii)

The condition (iv) defines an air space between the second and thirdlens components. When the upper limit of the condition (iv) is exceeded,the overall length of a lens system increases and it is difficult toreduce astigmatism over the entire image plane. When the lower limit ofthe condition (iv) is exceeded, it is impossible to obtain a sufficienteffective aperture due to the mechanical interference between the secondand third lens components.

The condition (v) defines thickness of the third lens component. Whenthe upper limit of the condition (v) is exceeded, astigmatism isadvantageously reduced over the entire image plane but the overalllength is apt to increase. When the lower limit of the condition (v) isexceeded, it is difficult to correct astigmatism.

The condition (vi) defines an air space between the first and secondlens components. When the upper limit of the condition (vi) is exceeded,it is difficult to correct spherical aberrations and chromaticaberrations. In addition, the overall length of a lens system is apt toincrease. When the lower limit of the condition (vi) is exceeded, it isimpossible to obtain a sufficient effective aperture due to themechanical interference between the first and second lens components tocause a shortage of a quantity of marginal rays.

The condition (vii) defines a focal length of the fourth lens component.When the upper limit of the condition (vii) is exceeded, aberrations areadvantageously corrected but the overall length of a lens system is aptto increase. When the lower limit of the condition (vii) is exceeded, itis easy to reduce the overall length but correction of aberrationsbecomes inconvenient. In particular, offaxial aberrations (coma anddistortion) are not fully corrected even if an aspherical surface isintroduced.

The condition (viii) defines the Abbe's number of a convex lens of thethird lens component and is for correcting chromatic coma of lower siderays in offaxial aberrations. When ν₃ (ν_(3b) in Embodiment 3) is morethan 58, the g line of the lower side rays is overcorrected, namelylateral aberration is apt to disadvantageously become a negatively largevalue.

Referring now to the drawings, Embodiments of the present invention willbe described below. In the drawings, r₁ through r₉ represents radii ofcurvature on the surfaces of the respective lens elements, d₁ through d₇represent thickness of the respective lens elements and airspacestherebetween, n₁ through n₄ represent refractive indices of therespective lens elements and ν₁, ν₂, . . . , ν₄ represent Abbe's numbersof the respective lens elements.

    ______________________________________                                        Embodiment 1                                                                  F/3.5, f = 100                                                                r.sub.1 = 27.3450                                                             d.sub.1 = 10.2642                                                                            n.sub.1 = 1.71300                                                                          ν.sub.1 = 53.84                                r.sub.2 = 66.4902                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -170.0328                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 40.3043                                                             d.sub.4 = 3.8124                                                              r.sub.5 = 49.0974                                                             d.sub.5 = 9.7950                                                                             n.sub.3 = 1.62588                                                                          ν.sub.3 = 35.70                                r.sub.6 = -76.4065                                                            d.sub.6 = 16.0130                                                             r.sub.7 = -16.3299                                                            d.sub.7 = 3.8124                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -22.7751 (aspherical                                                surface                                                                       Telephoto ratio = 0.999                                                       f.sub.1.2.3 = 70.308                                                                             f.sub.4 = -145.663                                         Aspherical constant;                                                                             A = -0.16357 ×  10.sup.-6,                                              B = -0.96563 × 10.sup.-8,                                               C = 0.48176 × 10.sup.-11                                                D = 0.59552 × 10.sup.-17                             Embodiment 2                                                                  F/3.5, f = 100                                                                r.sub.1 = 27.1336                                                             d.sub.1 = 9.9707                                                                             n.sub.1 = 1.69350                                                                          ν.sub.1 = 53.23                                r.sub.2 = 75.7176                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -155.5389                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 41.2871                                                             d.sub.4 = 4.1056                                                              r.sub.5 = 55.1050                                                             d.sub.5 = 9.7947                                                                             n.sub.3 = 1.63636                                                                          ν.sub.3 = 35.37                                r.sub.6 = -71.0312                                                            d.sub.6 = 15.6137                                                             r.sub.7 = -17.1978                                                            d.sub.7 = 3.8123                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 =  57.50                               r.sub.8 = -25.1689 (aspherical                                                surface)                                                                      Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.636                                                          f.sub.4 = -131.001                                                            Aspherical constant;                                                                             A = 0.14440 × 10.sup.-6,                                                B = -0182134 × 10.sup.-8,                                               C = 0.48225 × 10.sup.-11,                                               D = 0.59341 × 10.sup.-17,                            Embodiment 3                                                                  F/2.8, f = 100                                                                r.sub.1 = 31.7092                                                             d.sub.1 = 8.7977                                                                             n.sub.1 = 1.74100                                                                          ν.sub.1 = 52.68                                r.sub.2 = 106.7411                                                            d.sub.2 = 2.0528                                                              r.sub.3 = -388.0983                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.80518                                                                          ν.sub.2 = 25.43                                r.sub.4 = 69.5001                                                             d.sub.4 = 8.4165                                                              r.sub.5 = 123.2508                                                            d.sub.5a = 2.6394                                                                            n.sub.3a = 1.51633                                                                         ν.sub.3a = 64.15                               r.sub.6 = 44.6919                                                             d.sub.5b = 12.0235                                                                           n.sub.3b = 1.62012                                                                         ν.sub.3b = 49.66                               r.sub.7 = -114.4013                                                           d.sub.6 = 16.2438                                                             r.sub.8 = -19.0197                                                            d.sub.7 = 3.4311                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.9 = -31.5797 (aspherical                                                surface)                                                                      Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.446                                                                             f.sub.4 = -106.789                                         Aspherical constant;                                                                             A = 0.19703 × 10.sup.-6,                                                B = =0.12836 × 10.sup.-7,                                               C = 0.29033 × 10.sup.-10                                                D = -0.41649 × 10.sup.-13                            ______________________________________                                    

What is claimed is:
 1. A compact photographic camera lens system ofshort overall length, comprising:a first positive meniscus lenscomponent having a convex surface on the object side thereof; a secondbiconcave lens componet; a third biconvex lens component; and a fourthnegative meniscus lens component; said fourth lens component having onlyone aspherical surface which is provided on the image side thereof, saidaspherical surface being given by the following equation ##EQU2## wherethe sum of all the terms other than the component representing thespherical surface is expressed by

    Ay.sub.8.sup.4 +By.sub.8.sup.6 +Cy.sub.8.sup.8 +Dy.sub.8.sup.10 =Δx.sub.8,

with the conditions Δx₈ ≦0 and |Δx₈ |≦5×10⁻⁴ f, (y₈ ≦0.1f) beingsatisfied and with the further conditions |Ay₈ ⁴ |≦0.1|By₈ ⁶ | with thelimits of at least 0.15f≦y₈ ≦0.2f also being satisfied, wherein frepresents a focal length of the total system and A, B, C and Drepresent aspherical constants.
 2. A compact photographic camera lenssystem of the type described in claim 1 wherein said third biconvex lenscomponent consists of a compound lens.
 3. A compact photographic cameralens system according to claim 1 in which the lens system is designed tosatisfy the following conditions:

    0.45f<f.sub.1.2.3 <0.75f                                   (ii)

    0.15f<d.sub.6 <0.2f                                        (iii)

wherein f represents a focal length, f₁.2.3 represents a resultant focallength of the lens group consisting of said first through third lenscomponents, and d₆ represents air space between said third and fourthlens components.
 4. A compact photographic camera lens system accordingto claim 3 wherein, in order to further improve the correction ofaberrations, the lens system is further modified as follows:

    0.02f<d.sub.4 <0.087f                                      (iv).


5. A compact photographic camera lens system according to claim 3 inorder to further improve the correction of aberrations, the lens systemof further modified as follows:

    0.09f<d.sub.5 <0.16f                                       (iv).


6. A compact photographic camera lens system according to claim 3wherein, in order to further improve the correction of aberrations, thelens system is further modified as follows:

    0.02f<d.sub.2 <0.04f                                       (iv).


7. A compact photographic camera lens system according to claim 3wherein, in order to further improve the correction of aberrations, thelens system is further modified as follows:

    0.05f<|f.sub.4 |<2.00f                   (iv).


8. A compact photographic camera lens system according to claim 3wherein, in order to further improve the correction of aberrations, thelens system is further modified as follows:

    v.sub.3 <58.0                                              (iv).


9. A compact photographic camera lens system according to claim 1, inwhich said third lens component comprises a single lens and has thefollowing values:

    ______________________________________                                        r.sub.1 = 27.1336                                                             d.sub.1 = 9.9707                                                                             n.sub.1 = 1.69350                                                                          ν.sub.1 = 53,23                                r.sub.2 = 75.7176                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -155.5389                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 25.22                                r.sub.4 = 41.2871                                                             d.sub.4 = 4.1056                                                              r.sub.5 = 55.1050                                                             d.sub.5 = 9.7947                                                                             n.sub.3 = 1.63636                                                                          ν.sub.3 = 35.37                                r.sub.6 = 71.0312                                                             d.sub.6 = 15.6137                                                             r.sub.7 = -17.1978                                                            d.sub.7 = 3.8123                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -25.1689 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.636                                                          f.sub.4 = -131.001                                                            Aspherical constant;                                                          A = 0.14440 × 10.sup.-6,                                                                   B = -0.82134 × 10.sup.-8                             C = 0.48225 × 10.sup.-11,                                                                  D = 0.59341 × 10.sup.-7                              ______________________________________                                    

Wherein: r=Radius of curvature of each surface of a lens in order fromthe object side; d=Thickness of each lens and spacing between lenses inorder from the object side; n=Radius index of each lens in order fromthe object side; and v=Abbe number of each lens in order from the objectside.
 10. A compact photographic camera lens system according to claim1, in which said third lens component comprises a compound lens composedof negative and positive lenses and has the following values:

    ______________________________________                                        r.sub.1 = 31.7092                                                             d.sub.1 = 8.7977                                                                             n.sub.1 = 1.74100                                                                          ν.sub.1 = 52.68                                r.sub.2 = 106.7411                                                            d.sub.2 = 2.0528                                                              r.sub.3 = -388.0983                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.80518                                                                          ν.sub.2 = 25.43                                r.sub.4 = 69.5001                                                             d.sub.4 = 8.4165                                                              r.sub.5 = 123.2508                                                            d.sub.5a = 2.6394                                                                            n.sub.3a = 1.51633                                                                         ν.sub.3a = 64.15                               r.sub.6 = 44.6919                                                             d.sub.5b = 12.0235                                                                           n.sub.3b = 1.62012                                                                         ν.sub.3b = 49.66                               r.sub.7 = -114.4013                                                           d.sub.6 = 16.2438                                                             r.sub.8 = -19.0197                                                            d.sub.7 = 3.3411                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.9 = -31.5797 (aspherical                                                surface)                                                                      F/2.8, f = 100                                                                f.sub.1.2.3 =  -68.446                                                                           f.sub.4 = -106.789                                         Aspherical constant;                                                          A = 0.19703 × 10.sup.-6,                                                                   B = -0012836 × 10.sup.-7                             C = 0.29033 × 10.sup.-10,                                                                  0.41649 × 10.sup.-13.                                ______________________________________                                    

Wherein: r=Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 11. A compact photographic camera lens systemaccording to claim 1 further satisfying the following conditions

    0.02<d.sub.4 <0.087f                                       (iv)

    0.09f<d.sub.5 <0.16f                                       (v)

    0.02f<d.sub.2 <0.04f                                       (vi)

    0.5f<|f.sub.4 |<2.0f                     (vii)

    ν.sub.3 <58.0                                           (viii)

wherein d represents lens thickness and air space and ν₃ represents theAbbe's number of glass of said third biconvex lens component.
 12. Acompact photographic camera lens system according to claim 11, in whichsaid third lens component comprises a single lens and has the followingvalues:

    ______________________________________                                        r.sub.1 = 27.3450                                                             d.sub.1 = 10.2642                                                                            n.sub.1 = 1.71300                                                                          ν.sub.1 = 53.84                                r.sub.2 = 66.4902                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -170.0328                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 40.3043                                                             d.sub.4 = 3.8124                                                              r.sub.5 = 49.0974                                                             d.sub.5 = 9.7950                                                                             n.sub.3 = 1.62588                                                                          ν.sub.3 = 35.70                                r.sub.6 = -76.4065                                                            d.sub.6 = 16.0130                                                             r.sub.7 = -16.3299                                                            d.sub.7 = 3.8124                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -22.7751 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ration = 0.999                                                      f.sub.1.2.3 = 70.308                                                                             f.sub.4 = 145.663                                          A = -0.16357 × 10.sup.-6,                                                                  B = -0.96563 × 10.sup.-8                             C = 0.48176 × 10.sup.-11,                                                                  D = 0.59552 × 10.sup.-17.                            ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 13. A compact photographic camera lens systemaccording to claim 11, in which said third lens component comprises asingle lens and has the following values:

    ______________________________________                                        r.sub.1 = 27.1336                                                             d.sub.1 = 9.9707                                                                             n.sub.1 = 1.69350                                                                          ν.sub.1 = 53,23                                r.sub.2 = 75.7176                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -155.5389                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 25.22                                r.sub.4 = 41.2871                                                             d.sub.4 = 4.1056                                                              r.sub.5 = 55.1050                                                             d.sub.5 = 9.7947                                                                             n.sub.3 = 1.63636                                                                          ν.sub.3 = 35.37                                r.sub.6 = 71.0312                                                             d.sub.6 = 15.6137                                                             r.sub.7 = -17.1978                                                            d.sub.7 = 3.8123                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -25.1689 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.636                                                          f.sub.4 = -131.001                                                            Aspherical constant;                                                          A = 0.14440 × 10.sup.-6,                                                                   B = -0.82134 × 10.sup.-8                             C = 0.48225 × 10.sup.-11,                                                                  D = 0.59341 × 10.sup.-7                              ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 14. A compact photographic camera lens systemaccording to claim 11, in which said third lens component comprises acompound lens composed of negative and positive lenses and has thefollowing values:

    ______________________________________                                        r.sub.1 = 31.7092                                                             d.sub.1 = 8.7977                                                                             n.sub.1 = 1.74100                                                                          ν.sub.1 = 52.68                                r.sub.2 = 106.7411                                                            d.sub.2 = 2.0528                                                              r.sub.3 = -388.0983                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.80518                                                                          ν.sub.2 = 25.43                                r.sub.4 = 69.5001                                                             d.sub.4 = 8.4165                                                              r.sub.5 = 123.2508                                                            d.sub.5a = 2.6394                                                                            n.sub.3a = 1.51633                                                                         ν.sub.3a = 64.15                               r.sub.6 = 44.6919                                                             d.sub.5b = 12.0235                                                                           n.sub.3b = 1.62012                                                                         ν.sub.3b = 49.66                               r.sub.7 = -114.4013                                                           d.sub.6 = 16.2438                                                             r.sub.8 = -19.0197                                                            d.sub.7 = 3.4311                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.9 = -31.5797 (aspherical                                                surface)                                                                      F/2.8, f = 100                                                                f.sub.1.2.3 =  -68.446                                                                           f.sub.4 = -106.789                                         Aspherical constant;                                                          A = 0.19703 × 10.sup.-6,                                                                   B = -0012836 × 10.sup.-7                             C = 0.29033 × 10.sup.-10,                                                                  0.41649 × 10.sup.-13.                                ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 15. A compact photographic camera lens systemaccording to claim 1, further satisfying the following conditions

    0.02<d.sub.4 <0.087f                                       (iv)

    0.09f<d.sub.5 <0.16f                                       (v)

    0.02f<d.sub.2 <0.04f                                       (vi)

    0.5f<|f.sub.4 |<2.0f                     (vii)

    v.sub.3 <58.0                                              (viii)

wherein d represents lens thickness and air space and v₃ represents theAbbe's number of glass of said third biconvex lens component.
 16. Acompact photographic camera lens system according to claim 15, in whichsaid third lens component comprises a single lens and has the followingvalues:

    ______________________________________                                        r.sub.1 = 27.3450                                                             d.sub.1 = 10.2642                                                                            n.sub.1 = 1.71300                                                                          ν.sub.1 = 53.84                                r.sub.2 = 66.4902                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -170.0328                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 40.3043                                                             d.sub.4 = 3.8124                                                              r.sub.5 = 49.0974                                                             d.sub.5 = 9.7950                                                                             n.sub.3 = 1.62588                                                                          ν.sub.3 = 35.70                                r.sub.6 = -76.4065                                                            d.sub.6 = 16.0130                                                             r.sub.7 = -16.3299                                                            d.sub.7 = 3.8124                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -22.7751 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.999                                                       f.sub.1.2.3 = 70.308                                                                             f.sub.4 = 145.663                                          A = -0.16357 × 10.sup.-6,                                                                  B = -0.96563 × 10.sup.-8                             C = 0.48176 × 10.sup.-11,                                                                  D = 0.59552 × 10.sup.-17.                            ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; andv = Abbe number of each lens in orderfrom the object side.
 17. A compact photographic camera lens systemaccording to claim 15, in which said third lens component comprises asingle lens and has the following values:

    ______________________________________                                        r.sub.1 = 27.1336                                                             d.sub.1 = 9.9707                                                                             n.sub.1 = 1.69350                                                                          ν.sub.1 = 53,23                                r.sub.2 = 75.7176                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -155.5389                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 25.22                                r.sub.4 = 41.2871                                                             d.sub.4 = 4.1056                                                              r.sub.5 = 55.1050                                                             d.sub.5 = 9.7947                                                                             n.sub.3 = 1.63636                                                                          ν.sub.3 = 35.37                                r.sub.6 = 71.0312                                                             d.sub.6 = 15.6137                                                             r.sub.7 = -17.1978                                                            d.sub.7 = 3.8123                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -25.1689 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.636                                                          f.sub.4 = -131.001                                                            Aspherical constant;                                                          A = 0.14440 × 10.sup.-6,                                                                   B = -0.82134 × 10.sup.-8                             C = 0.48225 × 10.sup.-11,                                                                  D = 0.59341 × 10.sup.-7                              ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 18. A compact photographic camera lens systemaccording to claim 15, in which said third lens component comprises acompound lens composed of negative and positive lenses and has thefollowing values:

    ______________________________________                                        r.sub.1 = 31.7092                                                             d.sub.1 = 8.7977                                                                             n.sub.1 = 1.74100                                                                          ν.sub.1 = 52.68                                r.sub.2 = 106.7411                                                            d.sub.2 = 2.0528                                                              r.sub.3 = -388.0983                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.80518                                                                          ν.sub.2 = 25.43                                r.sub.4 = 69.5001                                                             d.sub.4 = 8.4165                                                              r.sub.5 = 123.2508                                                            d.sub.5a = 2.6394                                                                            n.sub.3a = 1.51633                                                                         ν.sub.3a = 64.15                               r.sub.6 = 44.6919                                                             d.sub.5b = 12.0235                                                                           n.sub.3b = 1.62012                                                                         ν.sub.3b = 49.66                               r.sub.7 = -114.4013                                                           d.sub.6 = 16.2438                                                             r.sub.8 = -19.0197                                                            d.sub.7 = 3.4311                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.9 = -31.5797 (aspherical                                                surface)                                                                      F/2.8, f = 100                                                                f.sub.1.2.3 =  -68.446                                                                           f.sub.4 = -106.789                                         Aspherical constant;                                                          A = 0.19703 × 10.sup.-6,                                                                   B = -0012836 × 10.sup.-7                             C = 0.29033 × 10.sup.-10,                                                                  0.41649 × 10.sup.-13.                                ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 19. A compact photographic camera lens systemaccording to claim 1, in which said third lens component comprises asingle lens and has the following values:

    ______________________________________                                        r.sub.1 = 27.3450                                                             d.sub.1 = 10.2642                                                                            n.sub.1 = 1.71300                                                                          ν.sub.1 = 53.84                                r.sub.2 = 66.4902                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -170.0328                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 40.3043                                                             d.sub.4 = 3.8124                                                              r.sub.5 = 49.0974                                                             d.sub.5 = 9.7950                                                                             n.sub.3 = 1.62588                                                                          ν.sub.3 = 35.70                                r.sub.6 = -76.4065                                                            d.sub.6 = 16.0130                                                             r.sub.7 = -16.3299                                                            d.sub.7 = 3.8124                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -22.7751 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephone ratio = 0.999                                                       f.sub.1.2.3 = 70.308                                                                             f.sub.4 = -145.663                                         A = -0.16357 × 10.sup.-6,                                                                  B = -0.96563 × 10.sup.-8                             C = 0.48176 × 10.sup.-11,                                                                  D = 0.59552 × 10.sup.-17.                            ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 20. A compact photographic camera lens systemaccording to claim 1, in which said third lens component comprises asingle lens and has the following values:

    ______________________________________                                        r.sub.1 = 27.3450                                                             d.sub.1 = 10.2642                                                                            n.sub.1 = 1.71300                                                                          ν.sub.1 = 53.84                                r.sub.2 = 66.4902                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -170.0328                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 40.3043                                                             d.sub.4 = 3.8124                                                              r.sub.5 = 49.0974                                                             d.sub.5 = 9.7950                                                                             n.sub.3 = 1.62588                                                                          ν.sub.3 = 35.70                                r.sub.6 = -76.4065                                                            d.sub.6 = 16.0130                                                             r.sub.7 = -16.3299                                                            d.sub.7 = 3.8124                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -22.7751 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.999                                                       f.sub.1.2.3 = 70.308                                                                             f.sub.4 = -145.663                                         Aspherical constant;                                                          A = -0.16357 × 10.sup.- 6,                                                                 B = -0.96563 × 10.sup.-8,                            C = 0.48176 × 10.sup.-11,                                                                  D = 0.59552 × 10.sup.-17.                            ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 21. A compact photographic camera lens systemaccording to claim 1, in which said third lens component comprises asingle lens and has the following values:

    ______________________________________                                        r.sub.1 = 27.1336                                                             d.sub.1 = 9.9707                                                                             n.sub.1 = 1.69350                                                                          ν.sub.1 = 53.23                                r.sub.2 = 75.7176                                                             d.sub.2 = 2.9326                                                              r.sub.3 = -155.5389                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.78470                                                                          ν.sub.2 = 26.22                                r.sub.4 = 41.2871                                                             d.sub.4 = 4.1056                                                              r.sub.5 = 55.1050                                                             d.sub.5 = 9.7947                                                                             n.sub.3 = 1.63636                                                                          ν.sub.3 = 35.37                                r.sub.6 = -71.0312                                                            d.sub.6 = 15.6137                                                             r.sub.7 = 17.1978                                                             d.sub.7 = 3.8123                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.8 = -25.1689 (aspherical                                                surface)                                                                      F/3.5, f = 100                                                                Telephoto ratio = 0.994                                                       f.sub.1.2.3 = 68.636                                                          f.sub.4 - -131.001                                                            Aspherical constant;                                                          A = 0.14440 × 10.sup.-6,                                                                   B = -0.82134 × 10.sup.-8                             C = 0.48225 × 10.sup.-11,                                                                  D = 0.59341 × 10.sup.-17.                            ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.
 22. A compact photographic camera lens systemaccording to claim 1, in which said third lens component comprises acompound lens composed of negative and positive lenses and has thefollowing values:

    ______________________________________                                        r.sub.1 = 31.7092                                                             d.sub.1 = 8.7977                                                                             n.sub.1 = 1.74100                                                                          ν.sub.1 = 52.68                                r.sub.2 = 106.7411                                                            d.sub.2 = 2.0528                                                              r.sub.3 = -388.0983                                                           d.sub.3 = 2.9326                                                                             n.sub.2 = 1.80518                                                                          ν.sub.2 = 25.43                                r.sub.4 = 69.5001                                                             d.sub.4 = 8.4165                                                              r.sub.5 = 123.2508                                                            d.sub.5a = 2.6394                                                                            n.sub.3a = 1.51633                                                                         ν.sub.3a = 64.15                               r.sub.6 = 44.6919                                                             d.sub.5b = 12.0235                                                                           n.sub.3b = 1.62012                                                                         ν.sub.3b = 49.66                               r.sub.7 = -114.4013                                                           d.sub.6 = 16.2438                                                             r.sub.8 = -19.0197                                                            d.sub.7 = 3.4311                                                                             n.sub.4 = 1.49216                                                                          ν.sub.4 = 57.50                                r.sub.9 = -31.5797 (aspherical                                                surface)                                                                      F/2.8, f = 100                                                                f.sub.1.2.3 =  68.446                                                                            f.sub.4 = -106.789                                         Aspherical constant;                                                          A = 0.19703 × 10.sup.-6,                                                                   B = -0.12836 × 10.sup.-7,                            C = 0.29033 × 10.sup.-10,                                                                  D = -0.41649 × 10.sup.-13.                           ______________________________________                                    

Wherein: r = Radius of curvature of each surface of a lens in order fromthe object side; d = Thickness of each lens and spacing between lensesin order from the object side; n = Refractive index of each lens inorder from the object side; and v = Abbe number of each lens in orderfrom the object side.